1、在.h文件里:
#import <Foundation/Foundation.h> @interface NSObject (Property) @property (nonatomic, strong) id propretyName; @end
2、在.m文件里
#import "NSObject+Property.h" #import <objc/runtime.h> @implementation NSObject (Property) - (id)propretyName { return objc_getAssociatedObject(self, @selector(propretyName)); } - (void)setPropretyName:(id)propretyName { objc_setAssociatedObject(self, @selector(propretyName), propretyName, OBJC_ASSOCIATION_RETAIN_NONATOMIC); } @end